Backing plate is one of the important components of the PVD sputtering process. OFHC Copper (Oxygen free, high conductivity) is the commonly used material. It exhibits the best electrical and thermal characteristics.
Aluminum, Molybdenum and Stainless Steel can also be used for backing plate fabrication when Copper is not appropriate. As an example, the desired sputtering target material may have a non-compatible coefficient of expansion compared to that of Copper which can cause the bonded target assembly to fail irrecoverably. In such case, the use of an alternative backing plate metal is essential.